XF 1.4 Overlay Sub-Headings

How can I make some of the overlays that use the heading styling for the sub-heading use the sub-heading styling instead?

So, for example, one of the areas it's like this is the multi-quote overlay. How can I make the "Drag messages..." sub-heading be the same style as the sub-heading on the Moderation Actions overlay (Moderator, Action, Date)?

I figured it out while I was working on our framework. All this time I had been making the heading and sub-headings the same background color for consistency reasons, and I just figured out that was the cause of the "issue."

And I can just do the same for other areas like that. From looking at it further, the Moderator Actions one--the gray bar in my OP's second screenshot--uses primaryContent for its class, so I really can just use anything that's not a header-type styling.